The automotive industry has turned to the use of interior trim components such as door panels comprising a polyvinyl chloride shell. See, for example, the trim components disclosed in U.S. Pat. No. 3,123,403. The acceptance of such components has been because inter alia this type of construction permits a wide latitude in styling and color, and grain effects which are most desired particularly in the interior design of automobiles.
The current state of the art includes a pre-formed grained vinyl shell made from dry thermoplastic powder particles which are applied to a heated shell mold from a powder box to form a continuous monochromatic one-piece shell.
In order to enhance the interior decor of an automobile, interior door panels and other parts have been prepared which include two separate plastic shell sections formed from different colored plastic joined at a connection joint.
The use of multi-color plastic is also known in the manufacture of colored filaments. Such manufacture includes use of a compartmented spinning head for making two-colored yarn as disclosed in U.S. Pat. No. 3,049,397 issued Aug. 14, 1962 for Process of Making Space-Dyed Yarn.
Apparatus and method for multiple colored thermoplastic floor materials are set forth in U.S. Pat. No. 3,383,442 issued May 14, 1968.
Neither of the aforesaid methods and apparatus for manufacture or resultant manufacture is directed to a process or apparatus for manufacturing a single piece shell suitable for use as an interior panel component of an automobile.